How do I gracefully stop a System.Threading.Timer?

Question

I have a Windows Service implemented in C# that needs to do some work every so often. I\'ve implemented this using a System.Threading.Timer with a callback method t

Answer 1

Possible solution for protecting the callback method from working on a disposed timer:

https://stackoverflow.com/a/15902261/193178

Answer 2

As described in "Concurrent Programming on Windows":
Create a dummy class InvalidWaitHandle, inheriting from WaitHandle:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.ComponentModel;
using System.Data;
using System.Diagnostics;
using System.Threading;

namespace MyNameSpace
{
    class InvalidWaitHandle : WaitHandle
    {

    }
}

Hence you can Dispose a System.Threading.Timer properly like this:

public static void DisposeTimer()
{
   MyTimer.Dispose(new InvalidWaitHandle());
   MyTimer = null;
}

Answer 3

With this code

 timer = new Timer( state => {
                   // simulate some work that takes ten seconds
                   Thread.Sleep( tickInterval * 10 );

                   // when the work is done, schedule the next callback in one second
                   timer.Change( tickInterval, Timeout.Infinite );
               },
               null,
               tickInterval, // first callback in one second
               Timeout.Infinite );

it is almost certain that you will Dispose the timer while it is sleeping.

You will have to safeguard the code after Sleep() to detect a Disposed timer. Since there is no IsDisposed property a quick and dirty static bool stopping = false; might do the trick.

Answer 4

You do not need to dispose of the timer to stop it. You can call Timer.Stop() or set Timer.Enabled to false, either of which will stop the timer from running.